Having owned the bike for some time now and decided to do something about the harsh/choppy ride coming from the rear shock. Pulled the shock out and took the shock to a specialist.  The "Tech" measured my spring and dyno'd the shock. (I was looking for a problem)

Bike travelled 20,000miles/32,000 klm
Year 2009
Spring rate is 740 lbs (measured) Right on spec.

It does show the way the Compression and Rebound ratios work. 70/30 (70% rebound, 30%compression)

Also showing dyno of the shock run to 90 degrees C / 194 F  (showing heat fade).

I thought other members might be interested in this information.

Basically everything is with in spec. I will have to look elsewhere for a solution.

Going to replace the shock with an after market Shock.

This is certainly the first posting of such information about the stock shock I have seen.  Of course, it doesn't mean a whole lot to me   Brian will dig it, though...

I would love to know what the spring rate of 2011 and the new 2015 models are rated at. I think the 2010 onwards had a softer rear spring. Do you know if that is the case?

I would love to know what the spring rate of 2011 and the new 2015 models are rated at. I think the 2010 onwards had a softer rear spring. Do you know if that is the case?

I can't comment on the 2015 model, but Racetech shows 2008-2014 stock rear shock spring rate as being 13.3kg/mm.

Edit: I went from a 2008 model to a 2010 model, and I simply transferred all the suspension settings from the 08 over to the 10 model, and both bikes felt exactly the same. If the 2nd gen bikes had different springs, I didn't notice.

Not sure if there were rear suspension changes on the 2015 model or not...one of the guys here will likely know.

Rem

Reading about the new 2015 says.....

- NEW Stiffer rear suspension settings for enhanced control and carrying ability

I have just read more and found this......

-The adjustable rear suspension was stiffened on the initial preload setting to maintain the motorcycle’s legendary stability when carrying a passenger and full luggage.

So I have now answered my own question. The spring has not changed only the preload.

Never knew you could dyno a shock.

I was in the work shop and the guy was very helpful,  showing me the system for measuring the spring rate and the putting the shock on a special machine linked to a computer. If you look at the graph.... He ran the shock 3 x,  each a differant color. 1x at rebound fully closed. 1 x at half way.. 1x at fully backed off.  Shows the way the shock performed at each setting..

I can't comment on the 2015 model, but Racetech shows 2008-2014 stock rear shock spring rate as being 13.3kg/mm.

Edit: I went from a 2008 model to a 2010 model, and I simply transferred all the suspension settings from the 08 over to the 10 model, and both bikes felt exactly the same. If the 2nd gen bikes had different springs, I didn't notice.

Not sure if there were rear suspension changes on the 2015 model or not...one of the guys here will likely know.

Rem

think racetech is still wrong about the front springs and bike weight. was not fun learning about that.
traxxion now

http://shop.penskeshocks.com/PENSKE-RACING-SHOCKS-8983-REMOTE-PIGGY-BACK-DOUBLE-ADJUSTABLE/   

think racetech is still wrong about the front springs and bike weight. was not fun learning about that.
traxxion now

Oh I have no idea...I've not touched C14 suspension yet. I'm on my 2nd C14 with stock suspension, and I like it just the way it is.
I ride pretty hard, but I cannot ride the bike hard enough to out-ride the stock suspension. That is the one part of the bike I have ignored.

I've installed tons of RaceTech suspension components...Gold Valve kits, bushings, and springs...and I've had no issues with them personally.
I serviced about 25 sets of forks last year, and put gold valve kits in probably half a dozen of them.
As I said though...I usually leave my own stuff stock. (Installed dual Ohlins rear shocks on my 02 ZRX1200R a year or two ago).

My fork tools all came from Traxxion. The tools are great, and they were great to deal with, but that is the only experience I have with them.

Rem

The thing is that the stock suspension is great except for one thing. When you hit bumps (High speed) eg sharp edged bumps,  the stock suspension is to stiff and sends a jar up your spine. If you ride on smoother type roads, this is not a problem. Unfortunately our roads are  choppy and shows  that the initial compression is too stiff. Even the Dyno graph shows this.

I have ordered an "Nitron" shock with High, Low speed compression adjustment.

So I have now answered my own question. The spring has not changed; only the preload.

It's hard to know what exactly changed. All I can tell you is my bike has a factory setting of 10 'clicks' out of 24, where 2014s (and all other Gen2s, I assume) have 13 out of 30. Doing the math, both are about 0.42 of maximum preload. Maybe Kawi just meant that same stiffness is achieved with just 10 turns (vs 13). But 2015 bikes could still have a higher spring rate. We'll never going to know just by part number since due to a different preload system, they're going to be different for sure. And doubt the service manual goes into that kind of detail. Somebody would have to get that info from Kawasaki. I'm curious about that. Always riding solo and only weighing 155#, my bike definitely feels stiff. Still have to try it on a trip, but the good news is since I like a stiff sporty ride (for tackling the twisties aggressively), I should be able to adjust it for my liking within those 10 turns. It's not jarringly stiff right now, hence my comment.